When Bill Rasmussen launched the Entertainment Sports Programming Network (ESPN) in 1979, people in the TV industry called him crazy. More than 40 years later, however, ESPN is thriving, and there are dozens of other 24-hour sports networks available for fans of everything from football to fishing.

After getting fired from his job at the World Hockey Association, Rasmussen worked with a few fellow sports enthusiasts to create the first 30-minute sports program, which almost immediately grabbed a loyal audience. From there, Rasmussen and partner Ed Eagan set out to launch a full-time sports network. It was tough to raise the money and get cable and satellite networks to carry ESPN at first, but they were able to launch and had decent viewing numbers from the very start. From that ambitious beginning, 24-hour sports stations have grown into a multibillion dollar industry, with even extremely niche-focused sports networks pulling in millions in revenue.

One of the reasons 24-hour sports networks are so successful is that advertisers see live sports as "TiVo-proof" programming. Since watching sports is a social event for so many people, most sports fans aren't going to record a game to watch later -- they don't want to risk a spoiled ending by friends or coworkers who know the outcome of a big game.

Thanks to fan enthusiasm and the potential for high advertising revenue, 24-hour sports networks are booming. If your team's game isn't on the main ESPN channel, chances are you can catch it on one of the other dozens of 24-hour sports networks, like FOX Sports, CBS Sports or even one of the other multiple ESPN channels. There are even networks dedicated to reruns of classic sporting events, like ESPN Classic.

Not only have 24-hour sports networks made it easier for fans to follow their favorite teams, but they've also shaped the culture of sports by changing what we watch, how we watch and where we watch. Read on to learn more.

24-hour Sports

The 24-hour sports network model has been incredibly successful, and it's changed the way people watch sports and even when they watch. When sports reporting was relegated to local news broadcasts, it was nearly impossible for a New York Giants fan to keep up with the team if he was living in California. Now, fans can watch live games no matter where their favorite teams are playing.

Since these networks are broadcasting 24/7, they also show matches that never would have gotten airtime in the past. Soccer's popularity in the United States is a great example of how 24-hour sports networks have changed our preferences. Since so many soccer matches take place overseas, showing them live in the U.S. means broadcasting in the middle of the night. This used to be mainly a pay-per-view situation, but some 24-hour sports networks now offer soccer scores and even live streaming soccer online. The 2010 World Cup saw more than 3 million viewers per game in the U.S., and FOX even has a dedicated soccer channel available to around 40 percent of American viewers [source: MacAree].

Soccer isn't the only niche sport that has its own 24-hour channel now. Racing fans can watch the Speed Channel or Fuel TV, and for those with other interests, there's the dedicated Tennis Channel and even a World Fishing Network. When these niche networks aren't showing major events, they replay famous moments in the sport's history or air tutorials and tips from athletes.

These networks have even changed the face of sports bars. Of course, sports bars existed before 24-hour sports channels, but 24/7 sports has changed the neighborhood bar and given rise to national chains like ESPN Zone and FOX Sports Grill. Satellite and cable companies offer 24-hour sports packages for local sports bars, so fans can keep up with their teams at the local watering hole no matter what sports they follow or in which city their team is playing. Some bars will even adjust their hours to show overseas games.

Starting with ESPN and branching out to the dozens of sports networks on air today, 24-hour sports channels have changed the sports business and had an impact on how, when and where fans watch sports.

For more great articles on the impact of TV on society, check out the links on the next page.